Mechanical embedding

Embedded. Rectangular-cross-section aluminum fin which is wrapped under tension and mechanically embedded in a groove 0.25 0.05 mm (0.010 0.002 in) deep, spirally cut into the outside surface of a tube. 

There are two ways of handling the interaction between the QM region and MM region one way is to calculate electrostatic QM-MM interaction with the MM method (sometimes called mechanical embedding, or ME) and the other is to include the QM-MM interaction in the QM Hamiltonian (called electronic embedding or EE). The major difference is that in the ME scheme the QM wave function is the same in the gas phase and the electrostatic interaction is included classically, while in the EE scheme the QM wave function is polarized by the MM charges. The EE scheme is substantially more expensive than ME scheme, as the SCF iteration needs to be performed until self-consistency is achieved for QM electron distribution. Although the polarization effects are called important, as we will show later,... 

Cisneros GA, Na-Im Tholander S, Elking D, Darden TA, Parisel O, Piquemal J-P (2008) Simple formulas for improved point-charge electrostatics in classical force fields and hybrid Quantum Me-chanical/Molecular Mechanical embedding. Int J Quant Chem 108 1905... 

Rinse and buff immediately after the bulk CMP step. Rinsing removes the residual slurry and the polishing by-products including abraded film from the wafer, abraded polish pad material, and agglomerated slurry. Buffing removes most of the particles that are adhering to the surface as well as many mechanically embedded particles. 

Also in ONIOM(QM QM ), the interaction between the two layers is included at the low level of theory, and it can be regarded as mechanical embedding. In contrast to ONIOM(QM MM)-ME (mechanical embedding), phenomena such as polarization or charge transfer between the regions is included in ONIOM(QM QM ), albeit at the low level. The extension of ONIOM(QM QM ) to electronic embedding is currently in progress, but is more involved than it is for ONIOM(QM MM) [22],... 

With the above reservations we turn back to the interaction based classification of the hybrid QM/MM methods which allows us to distinguish the mechanical embedding, polarization embedding etc. We shall consider them subsequently. 

An alternative to anion and cation point charges is embedding the cluster into an array of overlapping anion and cation pseudopotentials, trying to capture some of the electron-electron interaction with the surrounding ceramic medium. A supplement to this is mechanical embedding... 

A Type A models are the simplest QM/MM models, using a simple mechanical embedding scheme. The QM/MM interactions are treated exactly as the same interactions would be in a purely classical MM calculation. 

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